Thanks for all the helpful replies from everyone. I can answer some of the
suggestions:

It's an 85 hedgecutter and I am leaving choke open when trying to re-start

Compression seems OK in comparison with other 2-stroke machines which I
have.

Idling is OK when cold but when hot I have to have the idle screw turned
right down to keep it running, but it still stalls by itself. It will only
keep running when hot if I keep the throttle almost fully open and the
engine running fast.

"Alan" wrote in message
ups.com...
[snip]
Next, check the tuning - should be 1 and 1.

I'm unsure what you mean by this??

Re. the plug: can someone give the correct plug type and grade for an HS-85?
I don't have a user manual for this.

I'll try the other tests suggested and report back! At present I can only
work it for about 10/15 minutes at a time, which is frustrating.

regards to all,
mutley